Improved traffic-signal light



Aug. 8, 1939'. Q sP m 2,168,831

IMPROVED TRAFFIC SIGNAL LIGHT Filed Dec. 1, 1936 2 Sheets-Sheet 2 ATTORNEY Patented Aug. 8, 1939 UNITED STATES PATENT OFFICE IMPROVED TRAFFIC-SIGNAL LIGHT Melvin 0. Speir, Austin, Tex.

Application December 1, 1936, Serial No. 113,682

2 Claims.

This invention relates to traffic signal lights and has for an object to provide novel means for synchronizing the operation of a group of lights at an intersection, the means including synchronizing electro-magnets associated with novel clutch mechanism for controlling the driving of the change warning disc.

A further object is to provide a traffie light having the change warning disc driven by a synchronous motor, the disc being of novel shape and carrying a lens through which a single bulb in the light shines as the disc rotates around semi-circular red and green panes so that drivers by watching the progress of the lens will be warned in ample time of an approaching change from red to green or vice versa.

A further object is to provide a traflic light which will be formed of a few strong simple and durable parts, which will be inexpensive to manufacture, and which will not easily get out of order. V .Withtheabove and other objects in view the invention consists of certain novel details of construction and combinations of parts hereinafter fully described and claimed, it being understood that variousmodifications may be resorted to within the scope ,ofthe appended claims without departing from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawings forming part of this specification,

Figure 1 is a front elevation of a traffic light constructed in accordance with the invention.

Figure 2 is a longitudinal sectional view of the traffic light taken on the line 2-2 of Figure 1.

Figure 3 is a cross sectional view of the traffic light taken on the line 3-3 of Figure 1.

Figure 4 is a front elevation of the traflic light with the face plate removed to expose the change warning disc.

Figure 5 is a longitudinal sectional view of the traffic light taken on the line 5-5 of Figure 2.

Figure 6 is a diagrammatic view showing a group of the change warning discs stopped in position for synchronizing and showing two of the four lights as having their change warning discs disposed at an angular advance of 180 degrees from the other two lights.

Referring now to the drawings in which like characters of reference designate similar parts in the various views, 10 designates a light casing of substantially conical shape and having a single lamp bulb ll disposed at the apex of the casing.

A synchronous motor I2 is mounted on a bracket arm l3 disposed in upright position in the casing.

The front of the casing is closed by a circular opaque face plate l4 having semi-circular wide slits l5 concentrically disposed and forming a 5, vertically split annulus, as best shown in Figure 1. A red pane l6, and a green pane H are mounted in rear of respectiveslits l5 and are held in place by an annular bracket l8.

A red lens l9 and. a green lens are disposed 10 in respective openings 2| and 22 located diametrically opposite each other outside of their respective red and green panes I6 and ii, at about midway the ends of said panes as best shown in Figure 1. 15

A change warning disc 23 is concentrically mounted loose on the shaft 24 of the synchronous motor l2 and is clutched thereto as will be presently described. The disc is uniformly reduced in diameter for one-half the length of its pe- 2 0 riphery to provide laterally extending edges 25 and 26 of greater length than the width of the lenses l9 and 2|] and to provide a semi-circular lobe 21 between these edges, of greater diameter than the outer diameter of both red and green 25 panes l6 and H as best shown by dotted lines 1 in Figure 1. 7

As a result of this particular shape of the disc when the disc is rotated the bulb H will shine through the arcuate space outside of the lobe 30 and the edges 25 and when the red and green lenses l6 and I1 are in registration alternately with this space each lens will be illuminated. In the position of the disc shown in Figure 5 each of the lenses is exposed for one-half its area which indicates that a change from red to green or vice versa is taking place.

For progressively indicating to drivers the time period remaining before a change will take place,

a lens 28 is mounted in an opening 29 in the lobe of the disc midway between the edges 25 and 26 and spaced from the center of the lobe at such a distance as to register with the red and green panes l6 and H as the warning disc rotates, as best shown in Figure 3. As a result during rotation of the warning disc 23 light rays from the bulb II will be projected through the lens 28 and through the particular pane either red or green along which the illuminated lens 28 is progressing.

The illuminated lens 28 will appear to a driver as a colored ball of. light advanced from one end of one of the panes to the opposite end and by watching the progress of the ball of light the driver may have visible evidence of the lapse of time from the beginning of either a red or green signal and will have ample time to prepare for the change when the end of the particular signal period is reached.

It is desirable that of each group of four lights at an intersection two of the lights will have their globes turned at an angular advance of 180 degrees from the other two lights as best illustrated diagrammatically in Figure 6, that is, the lobes of two of the warning discs will be located on the opposite side of. the driving shaft 24 than the other two discs. The purpose of this of course is to permit like colored signals to be displayed on the highway while the oppositely colored signals will be displayed on the cross street. For synchronizing warning discs so that this relative position will be constantly maintained each light is equipped with a synchronizing electro-magnet 30.

The synchronizing electro-magnet 3!] depends from the top of the casing II] in rear of the warning disc 23 and controls a clutch for de-clutching the disc from the motor shaft 24. The clutch comprises a rod 3| which is slidably secured in aligned guides 32 and terminates in a fork 33 which straddles the motor shaft 24. A helical spring 34 is secured at one end to the rear face of the lobe 21 of the disc and at the other end is connected to a cross bar 35 which connects the branches of the fork below the motor shaft.

To synchronize the group of warning discs 23 the control switch 36 of the current supply circuit 31, shown diagrammatically in Figure 6, is closed to simultaneously energize all of the electro-magnets 30 of the group. As each rod 3| is carried by its rotating disc into position to be afi'ected by the electro-magnet an armature 38 formed on the end of the rod is attracted by the core of the electro-magnet to move the rod endwise toward the electro-magnet and disengage the fork 33 from the motor shaft 24 so that the warning disc is de-clutched from the shaft and is held stationary. All of the warning discs of the group will thus become stationary in the desired position above described. The switch 36 may now be opened to de-energize the electromagnets whereupon the springs 34 contract and immediately draw the forks 33 of the rods 3| into frictional engagement with the shafts 24 of the synchronous motors, the motors thereafter maintaining synchronized rotation of the warning discs.

The casing I is equipped with a frame 3! which may be in the nature of a flat sheet of metal having the corners stepped as shown at 38 for the purpose of ornamentation. A lamp casing 39, best shown in Figures 2 and 5, is mounted on top of the casing II] in rear of the frame 31 which latter is provided with an opening 40 which is closed by a lens 4|. The lens is preferably colored red as indicative of fire alarm. A lamp bulb 42 is disposed in the lamp casing 39 and is controlled through any conventional fire alarm circuit.

Since a description of the operation has been given as a description of the parts progressed it is thought that the invention will be fully understood'without further explanation.

What is claimed is:

1'. A traffic light including a casing, signal means in the casing, a synchronous motor in the casing for operating said means, a shaft for the motor, a rod rotated in an orbit around said shaft by said signal means and having a fork straddling the shaft, a spring holding said fork normally frictionally clutched to the shaft, and an electromagnet disposed in the casing and adapted to intercept the rod and withdraw the rod endwise to declutch the fork from the shaft to permit the signal means to be synchronized.

2. A trafiic light including a casing, a signal means in the casing having a rotating shutter member, a synchronous motor in the casing having a shaft connected to said shutter for rotating the shutter, a forked rod mounted for endwise sliding movement on the shutter and having the fork thereof straddling the shaft, a spring connected to the rod for frictionally clutching the fork to the shaft, and an electro-magnet disposed in the casing and adapted to intercept and attract the rod to Withdraw the fork from the shaft and declutch the shaft from the shutter to permit synchronizing of the light.

MELVIN O. SPEIR. 

